The invention relates to a process for maintaining the sterility of a medical instrument, particularly in minimally invasive medical procedures, as well as an apparatus for carrying out the process.
In recent years, medical procedures, particularly operating techniques which make do with very small incisions in the body of the person or animal being treated, have acquired considerable importance and a completely new branch of medicine has arisen, so-called minimally invasive medicine.
The instruments used in this, such as endoscopes, arthroscopes, special endoscopic gripping and cutting devices, are designed for insertion in the body and for handling through a small incision and comprise parts which are inserted in particular in small diameter sleeves and in some cases are movable in the sleeves.
During the manipulation of the instruments in the patient's body it frequently occurs that body fluid enters the interior of the instrument, because of the capillary forces in the narrow gaps between the individual parts, leading to contamination. This internal contamination is very difficult or even impossible to remove once the procedure has ended and the sterility required can only be achieved under certain conditions. The practical service life of these expensive high precision instruments is therefore frequently far less than their actual technical service life.
In minimally invasive procedures in humans or animals, e.g. in the abdominal region (in laparoscopy), in the uterus (in hysteroscopy) or in the joints (in arthroscopy) it is necessary to widen the existing cavity by means of a gas, for which carbon dioxide is preferably used. The space thus formed creates a wide enough area of operation or observation allowing the operator to carry out the necessary medical interventions through the above-mentioned small access openings into the body cavity or into the organ or blood vessel.
This increase in pressure, which is unavoidable in order to achieve the necessary operating conditions in the majority of minimally invasive procedures, means that the pressure prevailing in the body cavity forces contaminated insufflation gas and/or body fluid into the instruments or endoscopic equipment used in the operation.
This further exacerbates the above mentioned problem of the internal contamination of the instruments.